Don't mark branches merged into a local main branch in the commits list

If a branch was merged into a local main branch, but the main branch
wasn't pushed yet, the commits list still marks the head of the branch
as part of a stack. For example, after merging wip into master locally,
the commits of master show a marker at the head of wip.

Pushing and pulling a stack leave such branches out since #6169, and the
markers disappear as soon as the main branch is pushed. Leave them out
of the markers too, so that the markers show the same stack.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

pkg/gui/presentation/commits.go

@@ -9,6 +9,7 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/commands/git_commands"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/common"
+	"github.com/jesseduffield/lazygit/pkg/gui/branchstack"
 	"github.com/jesseduffield/lazygit/pkg/gui/presentation/authors"
 	"github.com/jesseduffield/lazygit/pkg/gui/presentation/graph"
 	"github.com/jesseduffield/lazygit/pkg/gui/presentation/icons"
@@ -182,6 +183,9 @@ func GetCommitListDisplayStrings(
 		commits, common.UserConfig().Gui.CommitHashLength, fullDescription,
 		timeFormat, shortTimeFormat, now, bisectInfo)
 
+	mergedIntoLocalMainBranch := branchstack.CommitsMergedIntoLocalMainBranch(
+		commits, branches, common.UserConfig().Git.MainBranches)
+
 	lines := make([][]string, 0, len(filteredCommits))
 	var bisectStatus BisectStatus
 	willBeRebased := markedBaseCommit == ""
@@ -196,6 +200,7 @@ func GetCommitListDisplayStrings(
 			common,
 			commit,
 			branchHeadsToVisualize,
+			mergedIntoLocalMainBranch.Includes(commit.Hash()),
 			hasRebaseUpdateRefsConfig,
 			cherryPickedCommitHashSet,
 			isMarkedBaseCommit,
@@ -401,6 +406,7 @@ func displayCommit(
 	common *common.Common,
 	commit *models.Commit,
 	branchHeadsToVisualize *set.Set[string],
+	isMergedIntoLocalMainBranch bool,
 	hasRebaseUpdateRefsConfig bool,
 	cherryPickedCommitHashSet *set.Set[string],
 	isMarkedBaseCommit bool,
@@ -457,8 +463,9 @@ func displayCommit(
 		}
 
 		if branchHeadsToVisualize.Includes(commit.Hash()) &&
-			// Don't show branch head on commits that are already merged to a main branch
-			commit.Status != models.StatusMerged &&
+			// Don't show branch head on commits that are already merged to a
+			// main branch, be it its remote branch or the local one
+			commit.Status != models.StatusMerged && !isMergedIntoLocalMainBranch &&
 			// Don't show branch head on a "pick" todo if the rebase.updateRefs config is on
 			!(commit.IsTODO() && hasRebaseUpdateRefsConfig) {
 			tagString = style.FgCyan.SetBold().Sprint(

pkg/gui/presentation/commits_test.go

@@ -126,6 +126,37 @@ func TestGetCommitListDisplayStrings(t *testing.T) {
 		hash4 commit4
 						`),
 		},
+		{
+			testName: "don't show branch heads of branches merged into a local main branch",
+			commitOpts: []models.NewCommitOpts{
+				{Name: "commit1", Hash: "hash1", Parents: []string{"hash2"}},
+				{Name: "commit2", Hash: "hash2", Parents: []string{"hash3"}},
+				{Name: "commit3", Hash: "hash3", Parents: []string{"hash4"}},
+				{Name: "commit4", Hash: "hash4", Parents: []string{"hash5"}},
+				{Name: "commit5", Hash: "hash5", Status: models.StatusMerged},
+			},
+			branches: []*models.Branch{
+				{Name: "current-branch", CommitHash: "hash1", Head: true},
+				{Name: "other-branch", CommitHash: "hash2", Head: false},
+				{Name: "master", CommitHash: "hash3", Head: false},
+				{Name: "merged-into-local-master", CommitHash: "hash4", Head: false},
+			},
+			currentBranchName:         "current-branch",
+			hasUpdateRefConfig:        true,
+			startIdx:                  0,
+			endIdx:                    5,
+			showGraph:                 false,
+			bisectInfo:                git_commands.NewNullBisectInfo(),
+			cherryPickedCommitHashSet: set.New[string](),
+			now:                       time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC),
+			expected: formatExpected(`
+		hash1 commit1
+		hash2 * commit2
+		hash3 commit3
+		hash4 commit4
+		hash5 commit5
+						`),
+		},
 		{
 			testName: "show local branch head for head commit if updateRefs is on",
 			commitOpts: []models.NewCommitOpts{